[Effect of morphine, beta-endorphin, and met-enkephalin on electrical activity of Helix pomatia snail neurons].

Application of morphine and methionine-enkephaline using microionophoretic technique (20-100 nA, 1-15 sec) or perfusion (10(-7)--10(-6) M) caused inhibition of the impulsation, which in some of the cases was accompanied by hyperpolarization of the membrane and the decrease in its resistance, as well as by the reduction of EPSP's. The increase in impulsation with membrane depolarization was less frequent. beta-Endorphine (10(-7)--10(-6) M) caused a substantially longer inhibition of the impulse activity than morphine or met-enkephaline.